Process for rendering soil resistant to erosion with asphaltic oil-free petroleum resinous residue



PROCESS FOR RENDEG SOIL RESISTANT T EROSIGN WITH ASPHALTIC OIL-FREEPETRO- LEUM RESINOUS RESIDUE Mayer B. Goren and Bobby Gene Marquardt,Oklahoma City, Okla, assignors to Kerr-McGee Oil Industries Inc., acorporation of Delaware No Drawing. Application February 21, 1956 SerialNo. 566,772

18 Claims. (Cl. 47-58) 'This invention relates to a process for treatingsoil and more particularly to an improved process for rendering soilresistant to wind and water erosion.

It is desirable in many instances to provide a treating material and aprocess for rendering soil resistant to erosion. Heretofore, others haveproposed applying various types of continuous coatings to the soil toproduce a protective coating over the soil surface of a paintlikecharacter, but none of the prior proposals disclose the use of a soiltreating material and process which will provide the soil with anerosion-resistant surface film and a consolidated erosion-resistantlayer of soil beneath the film.

U.S. Patent No. 2,333,959, granted to Rollin J. Smith, discloses the useof a conventional asphaltic soil paint for use where the soil has beenfertilized and seeded before application of the paint. A continuouscoating of asphalt is applied to the soil surface and over the plants,roots, seed, etc., to form a temporary protective coating on the soilsurface of such a nature as to permit the infiltration of water andoxygen through cracks which form naturally in the coating.

Prior art asphaltic coatings have not been entirely satisfactory in soilstabilization practices for a number of reasons. For example, sinceapplied coating has been in the form of a paint-like coating coveringthe soil surface, it did not penetrate into the soil to any appreciabledepth. Damage to the protective asphaltic coating, such as by trafiicover the soil or by deterioration of the coating, and even cracks whichform naturally in the film, result in only partial protection of thesoil surface. The conventional bitumen cutbacks also have an adverseeffect upon the germination of seeds in many instances if brought, intodirect or prolonged contact therewith. Thus seeding and application ofthe soil paint could not always be carried out successfully in oneoperation.

We have discovered that when soil is treated witha water emulsion ofpetroleum resinous residue, the soil acquires desirable properties whichwere not heretofore possible or, in some respects, contemplated bysurface coatings of the prior art. Such emulsions, if applied inaccordance with the invention, will provide soil with a continuouserosion-resistant surface film, and will penetrate to a depth sufiicientto produce a continuous consolidated erosion-resistant layer of soilbeneath the surface film. As an additional advantage, the tilth of thesoil is improved.

Accordingly, it is a principal object of the present invention toprovide an improved process for effectively stabilizing soil againsterosion.

It is still a further'object of the invention to provide an inexpensiveprocess for effecting more permanent stabilization of soil againsterosion and which will allow the treated soil to carry some vehiculartraific.

It is a further object of the invention 'to provide a process forimproving the tilth of soil.

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The petroleum resinous residues suitable for treating soils inaccordance with the invention are petroleum resins, asphaltenes, andmixtures thereof. The preferred petroleum resins have softening pointsbetween about F. and 220 F. and are further characterized by anappreciable ductility for their softening points, while the preferredasphaltenes have softening points above 250 F. and are of a very friablenature.

of their preparation does not comprise a part of this invention.However, a preferred method for their prep- Q aration is described incopending U.S. patent applications Serial No. 435,944 filed June 10,1954, and Serial- No. 377,201, filed August 28, 1953 (both nowabandoned). Petroleum resinous residues thus prepared are substantiallyoil-free.

In treating soils where wind and water erosion is a major problem, weemulsify the petroleum resinous residues, preferably to form abitumen-in-water type emulsion and then apply this emulsion to the soil.A number of suitable methods for making butimen-inwater emulsions areknown in the art, a preferred method being disclosed in U.S. patentapplication Serial No. 448,158, filed August 5, 1954, now abandoned infavor of Serial No. 541,026, filed October 17, 1955. The emulsionsproduced by the method disclosed in U.S. patent application Serial No.448,158 are presently preferred due to their peculiar stabilitycharacteristics. Such emulsions have exceptional bulk stability, but inthin films the emulsions have a controlled stability which permits readypenetration into the soil before breaking to give a consolidated soillayer in a short period of time. Emulsions prepared from petroleumresinous residues having lower softening points and higher ductilitiesare not adversely affected by seasonal weather changes after applicationto soil in accordance with the process of the invention. However, thehigher softening point and lower ductility petroleum resinous residues,such as asphaltenes, should be plasticized with a suitable weatherresistant non-volatile plasticizer and preferably before preparation ofthe emulsion. The preferred plasticizers are relatively non-volatilefluid hydrocarbons having boiling points between 500 F. and 1000 F., andviscosities below 120 seconds Furol at 210 F., preferably below 100seconds Furol at 210 F. Specific examples of suitablefluidhydrocarbonplasticizers include gas oil and recycle oil from acatalytic cracker. sufiicient to properly plasticize petroleum resinousresidue will vary between about 10% and 50% by weight depending upon thesoftening point and ductility of the particular petroleum resinousresidue. Quantities of plasticizer as great as 10-20% by weight may beused in plasticizing petroleum resinous residue having a softeningpointof -250 F., while as much as 50% by weight plasticizer may be used inplasticizing asphaltenes having a softening point above 250 F. Theplasticizer should be present in concentrations great enough to give thepetroleum resinous residue substantial ductility.

Emulsions made by a suitable method described abo've and preferablycontaining from about 1 to 30% solids are uniformly applied by sprayingor other suitable purely economic except where, as pointed out below,the

Patented Mar. 8, 1960 The petroleum resinous residues may be made by anyof a number of suitable methods well known to the art and the manner.

The amount of plasticizer The rate of application is preferably 0.2 to

depth of penetration is to be controlled. stabilization is desired,quantifies as low as 0.05 gal. per sq. yd. may be applied. Suchemulsions penetrate the soil and coat both the surface and sub-surfacesoil particles with 'a thin co'ating of petroleum resinous residue.So'il thus treated is given'a very thin erosion-resistant surface filmof petroleum resinous residue and, in addition, a consolidated layer ofsoil is formed with the petroleum resinous residue beneath'this film,which layer is likewise erosion-resistant. It is apparent that theerosion-resistant qualities of soil treated by this method arenotdependent entirely upon the surface film and, in fact, the surface filmmay be destroyed by deterioration or light traffic without appreciablyaffecting the resistance to erosion of the soil. The treated soil willremain erosion-resistant solong'as at least a portion of theconsolidated soil layer If shallow li'zati'on effected by thesuperficial coatings of the prior going treatment is dependent to someextent on 'the type of soil being treated and the moisture content ofthe soil.

For example, a dry soil gives a lower penetration than a moist or veryWet soil. The depth of penetration of the emulsion and consolidation ofthe soil is also influenced by the percentage of solids in the treatingemulsion and the rate of application. If it is desired to consolidatethe soil toa depth of from /z to 1 inch, the emulsion may contain l -5'%solids and may be applied at the rate of 0.5-1 gal. per sq. yd. on mostsoils, or at a higher rate of application if a greater depth, such as 2to 2 /2 inches, is desired. A higher solid content emulsion maybe usedwhen a relatively thick surface film and shallower consolidation of thesoil is desired, or where somewhat deeper penetration is desired and thesoil is very moist or wet. The higher solid content emulsions givebetter results when used in treating highly porous or sandy-type soilsthan when used in treating tight or clayey-type soils.

One important advantage of using a bitumen-in-water type emulsion ofpetroleum resinous residue rather than a'conventional asphaltic cutbackis'that seed may be mixed with the emulsion without adverse effect upontheir germination; Thus the soil stabilization treatment and seeding maybe carried out simultaneously in one opera tion. This variation of ourprocess is highly desirable for use in permanently stabilizing roadshoulders, floodways, etc. since the treatment will permit the seeds tosprout and emerge through the erosion-resistant-soil. The surface filmand consolidated soil layer will oifer sufiicient resistance to wind andwater erosion to maintain a desired surface contour until a proper sodis obtained from the seeded plants.

Another variant of our process for treating soils is of importance innormal agricultural practices in the more arid'sections of the countrywhere wind and'dust erosion,

commonly called weather beating, destroys large acreages.

i Example A bitumen-in-water type emulsion of petroleum resin ousresidue was made in accordance with the teachings of copending patentapplication (now abandoned) Serial No. 448,158, filed August 5, 1954.This emulsion was let down to 2-6% solids and then applied to roadshoulders of a sandy to loamy type at the rate of 0.2 to 1 gal. per sq.yd. This treatment was made during winter months .to prevent erosion ofthe soil when a sod of plants could not be readily grown. The soil thustreated was examined and found to have a tough erosion-resistant film atits surface and then a consolidated layer of soil beneath this film of adepth from A to linch, the depth of the consolidated layer dependingupon the amount of emulsion applied per square yard and the moisturecontent of the soil when treated. It was also observed that lighttraflic sufficient to destroy the surface film did not appreciablyaffect the erosion-resistant qualities of the soil since theconsolidated layer was likewise effective in preventing erosion. Therewas no noticeable erosion on the treated shoulders duringthe'wintermonths, while similar'untreated shoulders 'eroded badly. Itwas further observed that the surface film was of such anature as toallow penetration of water and air directly into the soil despite thefactthat no cracking, scaling, or other deterioration of the surfacefilm was noted.

The treated road shoulders were lightly cultivated several months laterfor thepurpose of preparinga seed bed and then a letdown emulsion (5%solids) as above prepared and containing a suitable amount of seed wasapplied at the rate of 0.5 galpper sq. yd. This treatment consolidatedthe fresh soil layer to a. depth of about fii- /z inch, yet permittedthe seeds to sprout in the con solidated soil layer and emerge throughthe TOSlO11-.I'- sistant surface film. Untreated shoulders were alsoseeded at the same time.

Observation of the treated seeded areas and untreated areas showed thetreatment to be highly effective in preventing wind and water erosion.The treated soil was not subject to-noticeable wind and water erosionduring the period required for growing a sod and maintained the desiredsurface contour. The untreated soil eroded badly during this period.

The foregoing description of the present invention is for the purpose ofillustration only and is not limiting to the scope'thereof which is setforth in the claims.

What is claimed is:

l. A process for stabilizing soil against erosion comprising treatingthe soil with a substantially asphaltic oilfree petroleum resinousresidue-in-water emulsion to form a continuous erosion-resistant film'ofpetroleum resinous residue on the soil surface and a continuouserosionresistant consolidated soil layer beneath the film.

2. A process for stabilizing soil against erosion-comprising treatingthe soil with a substantially'asphaltic oilfree .asphaltene-in-wateremulsion to form a continuous erosion-resistant film of asphaltenes onthe soil surface and a continuous erosion-resistantconsolidated soillayer beneaththe film.

3. A process fol-stabilizing soil against erosion comprising treatingthe soil with a substantially asphaltic oilfree petroleum resin-in-wateremulsion to form a continuous erosion-resistant film of petroleum resinon the soil surface and a continuous erosion-resistant consolidated soillayer beneath the film.

'4. A process'for stabilizing soil against erosion c0mprising treatingthe soil with a substantially asphaltic oilfree petroleum resinousresidue-in-water emulsion con taining from 1-30% solids by weight toform acontinuouserosion-resistant'film of petroleum resinousresiduc onthe surface and acontinuous erosionaresistant :soil layer consolidatedby the petroleum resinuous residue beneath the. film.

5. A process forastabilizingsoil againsterosion comsolids by weight toform a continuous erosion-resistant film of asphaltenes on the soilsurface and a continuous erosion-resistant soil layer consolidated bythe asphaltenes beneath the film.

6. A process for stabilizing soil against erosion comprising treatingthe soil with a substantially asphaltic oilfree petroleum resin-in-wateremulsion containing from l-30% solids by weight to form a continuouserosionresistant film of petroleum resins on the soil surface and acontinuous erosion-resistant soil layer consolidated by the petroleumresin beneath the film.

7. A process for stabilizing soil against erosion comprising treatingthe soil with a water emulsion of a substantially asphaltic oil-freepetroleum resinous residue plasticized with 0.5 to 5% by weight of afluid. nonvolatie hydrocarbon boiling above 500 F. to form a continuouserosion-resistant film of petroleum resinous residue on the soil surfaceand a continuous erosionresistant consolidated soil layer beneath thefilm.

8. The process of claim 7 wherein the water emulsion contains from l to30% solids.

9. A process for permanently stabilizing soil against erosion comprisingtreating the soil with a substantially asphaltic oil-tree petroleumresinous residue-in-water type emulsion containing desired seed therein.

10. A process for permanently stabilizing soil against erosioncomprising treating the entire surface of the soil with a substantiallyaliphatic oil-free petroleum resinous residue-in-water type emulsiondiluted to 1 to 30% by weight petroleum resinous residue and containingdesired eed therein.

11. A process for permanently stabilizing soil against erosioncomprising treating the entire surface of the soil with a substantiallyasphaltic oil-free asphaltene-in-water emulsion diluted to 1 to 30% byweight asphaltene and containing desired seed therein.

12. A process for permanently stabilizing soil against erosioncomprising treating the entire surface of the soil with a substantiallyasphaltic oil-free resin-in-Water emulsion diluted to 1 to 30% by weightpetroleum resins and containing desired seed therein.

13. A composition for permanently stabilizing soil against erosioncomprising substantially asphaltic oil-free petroleum resinousresidue-in-water emulsion diluted to 1 to 30% by weight petroleumresinous residue and containing desired seed therein.

14. The composition of claim 13 wherein the petroleum resinous residueis asphaltenes.

15. The composition of claim 13 wherein the petroleum resinous residueis petroleum resins.

16. A composition for stabilizing soil against erosion comprisingsubstantially asphaltic oil-free petroleum resinous residue-in-wateremulsion containing desired seed therein.

17. The composition of claim 16 wherein the petroleum resinous residueis asphaltenes.

18. The composition of claim 16 wherein the petroleum resinous residueis petroleum resins.

References Cited in the file of this patent Publications: Myers et a1.,Some Experiences with Asphalt, published 1941 in Soil Science Society ofAmerica Proceedings 1941, vol. 6, pages 459, 460, 461.

Hackhs Chemical Dictionary, third edition, published 1944, page 80.

Wells: New Horticultural Methods, published Oct. 1947 in Roads andStreets (magazine), vol. 90, No. 10, pages 89, 90, 113.

Lentz: How to Grow Grass on Roadsides, published Apr. 1949 in PublicWorks (magazine), vol. 80, No. 4, pages 30, 31, 32.

Condenser Chemical Distionary, fourth edition, published 1950 byReinhold .(N.Y.), pages 566 and 567.

Garmhausen: Asphalt Mulch, published Feb. 1951 in Roads and Streets(magazine), vol. 94, No. 2, pages through 86.

Davis: Krilium for Crops, published January 1952 i in Chemistry(magazine), vol. 25, No. 5, pages 1 through 8.

Contractors and Engineers (magazine), published April 1953, vol. 50, No.4, pages 134 through 137. Article, Mulching Practices in SeedingRoadsides.

H. M. Smith: The Effect of Asphalt Mulches on the Stabilization of Soilsand Aggregate Materials and on Vcgetational Cover, published before Aug.19, 1953 as an Abstract of a Thesis, at University of Illinois, Urbana,Illinois. Eight pages.

UNITED" sTA'iE sPAT NT oFnca CERTIFIGATEOF coRnEo'noN Patent No.2,927,402 March a, 1960 Q Mayer B. Goren 'et al.

11115. hereby certified that error appears in the printed specificationof the above numbered patent requiring correction and that the saidLetters Patent should read as corrected below.

' Column 3, line 70, for "limited" read limiting column 5, line 27, foraliphatic read asphaltic Signed and 'sealed this 13th day of December1960.

J LsE L) litfies' tf I KARFHPAXLINE I v ROBERT c; wATsofw Att'esting;Officer i i y Colm'iissioner of Patents

1. A PROCESS FOR STABILIZING SOIL AGAINST EROSION COMPRISING TREATINGTHE SOIL WITH A SUBSTANTIALLY ASPHALTIC OILFREE PETROLEUM RESINOUSRESIDUE-IN-WATER EMULSION TO FORM A CONTINUOUS EROSION-RESISTANT FILM OFPETROLEUM RESINOUS RESIDUE ON THE SOIL SURFACE AND A CONTINUOUSEROSIONRESISTANT CONSOLIDATED SOIL LAYER BENEATH THE FILM.